Due to the recent vulnerability found on Log4j, We were tasked to move to version >= 2.16.0. Initially, my project was using <version>1.2.17</version>

After adding the necessary dependency, and making the necessary changes, on initiating a request I get the below error:

Caused by: java.lang.NoClassDefFoundError: Could not initialize class org.apache.logging.log4j.core.LoggerContext

My POM file

<dependencies>
        <dependency>
            <groupId>javax</groupId>
            <artifactId>javaee-api</artifactId>
            <version>8.0</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-api</artifactId>
            <version>2.16.0</version>
        </dependency>
        <dependency>
            <groupId>org.apache.logging.log4j</groupId>
            <artifactId>log4j-core</artifactId>
            <version>2.16.0</version>
        </dependency>
        <dependency>
            <groupId>com.squareup.okhttp3</groupId>
            <artifactId>okhttp</artifactId>
            <version>4.9.1</version>
        </dependency>
        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpclient</artifactId>
            <version>4.5.12</version>
        </dependency>
        <dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpcore</artifactId>
            <version>4.4.13</version>
            <type>jar</type>
        </dependency>
        <dependency>
            <groupId>org.json</groupId>
            <artifactId>json</artifactId>
            <version>20190722</version>
            <type>jar</type>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.47</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.10.2</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-annotations</artifactId>
            <version>2.10.2</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>2.10.2</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.dataformat</groupId>
            <artifactId>jackson-dataformat-xml</artifactId>
            <version>2.10.2</version>
        </dependency>
        <dependency>
            <groupId>org.codehaus.sonar</groupId>
            <artifactId>sonar-plugin-api</artifactId>
            <version>5.1</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>javax.validation</groupId>
            <artifactId>validation-api</artifactId>
            <version>2.0.0.Final</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>org.hibernate.validator</groupId>
            <artifactId>hibernate-validator-annotation-processor</artifactId>
            <version>6.0.2.Final</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.woodstox</groupId>
            <artifactId>woodstox-core</artifactId>
            <version>5.0.2</version>
        </dependency>
        <dependency>
            <groupId>org.apache.velocity</groupId>
            <artifactId>velocity</artifactId>
            <version>1.7</version>
        </dependency>
        <dependency>
            <groupId>org.apache.velocity</groupId>
            <artifactId>velocity-tools</artifactId>
            <version>2.0</version>
        </dependency>
        <dependency>
            <groupId>org.apache.poi</groupId>
            <artifactId>poi-ooxml</artifactId>
            <version>5.0.0</version>
        </dependency>



        <!-- Tests Dependencies -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.mockito</groupId>
            <artifactId>mockito-core</artifactId>
            <version>3.5.13</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.glassfish.jersey.core</groupId>
            <artifactId>jersey-common</artifactId>
            <version>2.22.2</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.hamcrest</groupId>
            <artifactId>hamcrest-core</artifactId>
            <version>1.3</version>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>org.eclipse.microprofile</groupId>
            <artifactId>microprofile</artifactId>
            <version>2.0.1</version>
            <type>pom</type>
            <scope>provided</scope>
        </dependency>

and my code and Log4J2 initialization

@Stateless
public class SessionKeyService {

    private static final Logger LOGGER = LogManager.getLogger(SessionKeyService.class);

    public String getSessionKeyID() {
        try {
            String url = properties.getProperty(Global.ENDPOINT_URL);

            ........

            SessionKey sessionKey = new SessionKey();
            sessionKey.setStatus(tokenObj.optString("Status"));
            sessionKey.setMessage(tokenObj.optString("Message"));
            sessionKey.setKey(tokenObj.optString("SessionKey"));

            return sessionKey.getKey();

        } catch (Exception ex) {
            LOGGER.error("Error: "+ex);
        }

        return null;
    }

Log4j2 XML file

<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="info" name="AppName" packages="">
    <Appenders>
        <Console name="LogToConsole" target="SYSTEM_OUT">
            <PatternLayout pattern="%d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %-5level %logger{36} - %m%n"/>
        </Console>
        <RollingFile name="LogToRollingFile" fileName="/opt/log/app-name.log"
                     filePattern="logs/$${date:yyyy-MM}/app-%d{MM-dd-yyyy}-%i.log.gz">
            <PatternLayout pattern="%d{yyyy-MM-dd HH:mm:ss.SSS} [%t] %-5level %logger{36} - %m%n"/>
            <Policies>
                <TimeBasedTriggeringPolicy />
                <SizeBasedTriggeringPolicy size="50 MB" />
            </Policies>
            <DefaultRolloverStrategy max="10"/>
        </RollingFile>

    </Appenders>
    <Loggers>
        <Root level="INFO">
<!--            <AppenderRef ref="syslogAppender" />-->
            <AppenderRef ref="LogToRollingFile"/>
            <AppenderRef ref="LogToConsole" />
        </Root>
    </Loggers>
</Configuration>

Please, I don't know where the LoggerContext is coming up.